# --header

Source: https://zshot-cli.com/reference/flags/browser/header/
Markdown: https://zshot-cli.com/reference/flags/browser/header/index.md
Section: [Reference](https://zshot-cli.com/reference/) › [Flags](https://zshot-cli.com/reference/flags/) › [Browser](https://zshot-cli.com/reference/flags/browser/)
CLI: `--header`, `-H` · REST: [`header`](https://zshot-cli.com/reference/server/api/schema/#header)
Value: `HEADER`

Sends a header, as `Name: value`, on each main-frame navigation within the target's registrable domain. Repeatable.

## Scope

The header follows a crawl or navigator session across same-site pages and subdomains. Subresource requests and navigations to another registrable domain go without it, so it never reaches third-party hosts. Cookies from [`--cookie`](/reference/flags/browser/cookie) follow cookie-jar rules instead and reach any matching request.

Under [`--server`](/reference/flags/server/server) it is a default for requests that send no `header`. Under `--cdp` it is ignored; set headers from the CDP client, such as with `Network.setExtraHTTPHeaders`.

## Example

**CLI**

```sh
zshot -f page.png \
  -H "X-Internal-Header: true" \
  https://zshot-cli.com/example_assets/hello_zshot/
```

**JSON** — `POST /` body for the [API](/reference/server/api), Pro license

```json
{
  "url": "https://zshot-cli.com/example_assets/hello_zshot/",
  "output_type": "png",
  "header": ["X-Internal-Header: true"]
}
```

**curl**

```sh
curl -X POST http://127.0.0.1:3000/ \
  -H "Content-Type: application/json" \
  -d '{"url":"https://zshot-cli.com/example_assets/hello_zshot/","output_type":"png","header":["X-Internal-Header: true"]}' \
  -o page.png
```

## Related

Flags:

- [`--cookie`](https://zshot-cli.com/reference/flags/browser/cookie/)
- [`--web-bot-auth`](https://zshot-cli.com/reference/flags/browser/web-bot-auth/)

Topics:

- [Public Suffix List](https://publicsuffix.org/)

## Navigation

- [Examples](https://zshot-cli.com/examples/)
- [Download](https://zshot-cli.com/download/)
- [Purchase](https://zshot-cli.com/purchase/)
- [Reference](https://zshot-cli.com/reference/)
  - [Formats](https://zshot-cli.com/reference/formats/)
  - [Flags](https://zshot-cli.com/reference/flags/)
    - [Common](https://zshot-cli.com/reference/flags/common/)
    - [Agents](https://zshot-cli.com/reference/flags/agents/)
    - [Archive](https://zshot-cli.com/reference/flags/archive/)
    - [Browser](https://zshot-cli.com/reference/flags/browser/)
      - [--accept-language](https://zshot-cli.com/reference/flags/browser/accept-language/)
      - [--browser-height](https://zshot-cli.com/reference/flags/browser/browser-height/)
      - [--browser-width](https://zshot-cli.com/reference/flags/browser/browser-width/)
      - [--chromium-arg](https://zshot-cli.com/reference/flags/browser/chromium-arg/)
      - [--chromium-preference](https://zshot-cli.com/reference/flags/browser/chromium-preference/)
      - [--cookie](https://zshot-cli.com/reference/flags/browser/cookie/)
      - [--device](https://zshot-cli.com/reference/flags/browser/device/)
      - [--device-list](https://zshot-cli.com/reference/flags/browser/device-list/)
      - [--device-scale-factor](https://zshot-cli.com/reference/flags/browser/device-scale-factor/)
      - [--emulate-dark-mode](https://zshot-cli.com/reference/flags/browser/emulate-dark-mode/)
      - [--emulate-disable-bluetooth](https://zshot-cli.com/reference/flags/browser/emulate-disable-bluetooth/)
      - [--emulate-disable-serial](https://zshot-cli.com/reference/flags/browser/emulate-disable-serial/)
      - [--emulate-disable-usb](https://zshot-cli.com/reference/flags/browser/emulate-disable-usb/)
      - [--emulate-geolocation](https://zshot-cli.com/reference/flags/browser/emulate-geolocation/)
      - [--emulate-gpu-renderer](https://zshot-cli.com/reference/flags/browser/emulate-gpu-renderer/)
      - [--emulate-gpu-vendor](https://zshot-cli.com/reference/flags/browser/emulate-gpu-vendor/)
      - [--emulate-hardware-concurrency](https://zshot-cli.com/reference/flags/browser/emulate-hardware-concurrency/)
      - [--emulate-media](https://zshot-cli.com/reference/flags/browser/emulate-media/)
      - [--emulate-memory](https://zshot-cli.com/reference/flags/browser/emulate-memory/)
      - [--emulate-mobile-device](https://zshot-cli.com/reference/flags/browser/emulate-mobile-device/)
      - [--emulate-timezone](https://zshot-cli.com/reference/flags/browser/emulate-timezone/)
      - [--emulate-touch-points](https://zshot-cli.com/reference/flags/browser/emulate-touch-points/)
      - [--emulate-vision-deficiency](https://zshot-cli.com/reference/flags/browser/emulate-vision-deficiency/)
      - [--full-page](https://zshot-cli.com/reference/flags/browser/full-page/)
      - **--header**
      - [--javascript](https://zshot-cli.com/reference/flags/browser/javascript/)
      - [--javascript-file](https://zshot-cli.com/reference/flags/browser/javascript-file/)
      - [--platform](https://zshot-cli.com/reference/flags/browser/platform/)
      - [--proxy-auth](https://zshot-cli.com/reference/flags/browser/proxy-auth/)
      - [--proxy-server](https://zshot-cli.com/reference/flags/browser/proxy-server/)
      - [--remove-modals](https://zshot-cli.com/reference/flags/browser/remove-modals/)
      - [--skip-robots-txt](https://zshot-cli.com/reference/flags/browser/skip-robots-txt/)
      - [--storage](https://zshot-cli.com/reference/flags/browser/storage/)
      - [--storage-chrome-profile](https://zshot-cli.com/reference/flags/browser/storage-chrome-profile/)
      - [--storage-chrome-profile-key](https://zshot-cli.com/reference/flags/browser/storage-chrome-profile-key/)
      - [--storage-firefox-profile](https://zshot-cli.com/reference/flags/browser/storage-firefox-profile/)
      - [--storage-limit](https://zshot-cli.com/reference/flags/browser/storage-limit/)
      - [--storage-safari-profile](https://zshot-cli.com/reference/flags/browser/storage-safari-profile/)
      - [--user-agent](https://zshot-cli.com/reference/flags/browser/user-agent/)
      - [--web-bot-auth](https://zshot-cli.com/reference/flags/browser/web-bot-auth/)
    - [Diagnostics](https://zshot-cli.com/reference/flags/diagnostics/)
    - [Document](https://zshot-cli.com/reference/flags/document/)
    - [Image](https://zshot-cli.com/reference/flags/image/)
    - [Navigator](https://zshot-cli.com/reference/flags/navigator/)
    - [Security](https://zshot-cli.com/reference/flags/security/)
    - [Server](https://zshot-cli.com/reference/flags/server/)
    - [Video](https://zshot-cli.com/reference/flags/video/)
  - [Agents](https://zshot-cli.com/reference/agents/)
  - [Configuration](https://zshot-cli.com/reference/configuration/)
  - [Crawling](https://zshot-cli.com/reference/crawling/)
  - [Docker](https://zshot-cli.com/reference/docker/)
  - [Exit Codes](https://zshot-cli.com/reference/exit_codes/)
  - [Linux](https://zshot-cli.com/reference/linux/)
  - [LLM Connections](https://zshot-cli.com/reference/llm_connections/)
  - [LLM Formatting](https://zshot-cli.com/reference/llm_formatting/)
  - [Local Inputs](https://zshot-cli.com/reference/inputs/)
  - [Navigator](https://zshot-cli.com/reference/navigator/)
  - [Security](https://zshot-cli.com/reference/security/)
  - [Server](https://zshot-cli.com/reference/server/)
  - [Shell completions](https://zshot-cli.com/reference/shell_completions/)
  - [Storage](https://zshot-cli.com/reference/storage/)
  - [Timeouts](https://zshot-cli.com/reference/timeouts/)
  - [Web Bot Auth](https://zshot-cli.com/reference/web_bot_auth/)
- [Support](https://zshot-cli.com/support/)
- [Changelog](https://zshot-cli.com/changelog/)

Site index: https://zshot-cli.com/llms.txt